Barry at Search engine round table has reported how google is now sending out penalty notices to spammy rich snippets
One site owner is commenting on the google webmaster forum over here regarding a notice he has received. The thread is worth reading with many voicing opinions on how pages shouldn't have authors and publishers, that ratings are on the wrong pages and so on..
It's a great warning for wp and alike user who download the "latest" plugin this duplicates what another plugin does or the cms itself down already.. Check out the google Rich Snippet guidelines here
I happy with google targeting this type of spam as we have all seen a brand new site appear with 1000+ 5/5 star rating!